501 flywheel timing marks

Camel, Sahara, Kanguro, Coguaro
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Haboola72
Posts: 95
Joined: 05 Jan 2013 15:03
Location: Tarragona, Spain

501 flywheel timing marks

Post by Haboola72 »

I'm confused by the timing marks on my '88 501 Camel flywheel.
Norbert gave a good description of it in a recent 'will not idle' thread in the 350 section.
It's the last cast Ducati electronica one before the Karkusan ignition bikes.The one with the air shovels. ( great description..)
It has PMS 1 and 2 as well as A350 and A500 for both front and rear cylinders. Six marks in all!

If I strobe time it to the A500 mark at 6000rpm it's ridiculously retarded on the pickup plate , the arrow at least 5mm to the right of the crankcase mark.
If I time it to the A350 mark its more or less OK , maybe a bit advanced. It pinks a bit.
I've decided to ignore either and adjust to optimum revs, then retard a few degrees . This puts the arrow on the cast notch.
It's all a bit confusing.
Is the A500 mark for the later Karkusan stator?
'It must be a .....'
Posts: 365
Joined: 12 Sep 2010 12:25

Re: 501 flywheel timing marks

Post by 'It must be a .....' »

Hi, all 500/501 engines have the same timing at 30 degrees before TDC (PMS). There is no timing difference between the Ducati Electronica and Kokusan systems.
Best to measure the rotor to check the marks/or to make new ones.
Timing on the 350s is 34 degrees before TDC (PMS).
Trust this helps?
Haboola72
Posts: 95
Joined: 05 Jan 2013 15:03
Location: Tarragona, Spain

Re: 501 flywheel timing marks

Post by Haboola72 »

Thanks for sorting that out!
The TMS mark on the flywheel rotor is spot on and the A500 mark is 30' to the right.
Maybe I'm mistaking pinking for the cylinder fins resonating , as some of the rubber baffles are missing.
Bike starts easily , plugs aren't showing lean. I just can't get a smooth progression to mid-range .
The bike came with stainless performance silencers, standard 501 jetting and no mid-range.
I've removed the small cone in the airbox which helped and the best set up so far is 130 main, 45 pilot and the X18 needle at 3rd groove.
Still not right.
'It must be a .....'
Posts: 365
Joined: 12 Sep 2010 12:25

Re: 501 flywheel timing marks

Post by 'It must be a .....' »

Hi, the first series 501 Camel and the later 501 Camel with electric start both had the same carb settings: Pilot jet 42, Starter jet 50, Needle X18 (2nd groove), Slide 40 and Main jet 76. I didn't make a note of the atomisers but the 501 Coguaru has BC 264 atomisers and 55 Pilot jets and the other settings are the same as the Camels.
It is possible to assemble the airbox internals incorrectly which may be your problem?
I have done several thousand miles on a first series Camel fitted with Leo Vinci exhausts with no changes to the carbs; it was a bit too loud yet it ran very well.
At the moment I have a 501 Coguaru engine in a 500 Camel chassis which is breathing through the 500 air box and it has a more open silencer; the carbs were initially jetted as a 501 Camel but it wouldn't rev beyond 4,500 revs until I replaced the 76 Main jet with a 128. I messed about for ages with carbs and almost everything else before I found the problem.
Therefore I would suggest that your current carb settings can't be too far off and perhaps the problem is elsewhere?
Hope this Helps,
PS I'm using a Ducati Electronica Ignition and charging system on the 501 Coguaru.
Haboola72
Posts: 95
Joined: 05 Jan 2013 15:03
Location: Tarragona, Spain

Re: 501 flywheel timing marks

Post by Haboola72 »

From the info you 've posted I may be tempted to replace the airbox cone, go back to standard settings and try a bigger main jet.
The 'performance' cans on mine presumably aid better exhaust flow , but these, if anything , are quieter than the originals..

Regarding the modifications to your camel/coguaro, I guess the 500 camel airbox is less restrictive than the flowerpot arrangement on the 501.

Very helpful and many thanks!
Pete
'It must be a .....'
Posts: 365
Joined: 12 Sep 2010 12:25

Re: 501 flywheel timing marks

Post by 'It must be a .....' »

Hi, regarding the differences between the 500 and 501 airboxes; comparing the filter and inlet port areas etc it would appear that the 501 is more free flowing?
As I said I did lots of messing about before my bike would rev out; mostly with the carbs, filters and exhaust (adjustable for flow), it didn't help that the new jets I bought (Original Dellorto) were not bored to the right size!
My 500 airbox had additional holes drilled in it which made no difference at all (now blocked).

As a starting point I would put a new dedicated balance pipe linking the carbs to eliminate the vacuum tap (use reserve to test) and the emissions valve; you can easily and quickly do this without removing the tank. If there is no change in running, then look the carbs and airfilter assembly.
Hope this helps, Ian
PS Only change one thing at a time!
Haboola72
Posts: 95
Joined: 05 Jan 2013 15:03
Location: Tarragona, Spain

Re: 501 flywheel timing marks

Post by Haboola72 »

Ian,
there was no emissions valve, just a T piece to the the carbs and vacuum fuel tap which didn't work. I rebuilt the tap and after a while blanked the hose off and ran the bike on one tap, easier when you're constantly removing the tank and playing with the carbs.
I did install a balance pipe but now I've blanked the vacuum nozzles in between sessions with the manometer!
This bike has been rebuilt from the chassis up and seems eager to surprise me on a weekly basis. Last week one of the idling screws dropped out on the road , gone. It took a while to realise why starting had become difficult. Then one of the clutch nuts sheared off, at 5000 rpm, exploding nut and spring into a very confined space , turning a neat crescent on the inside of the clutch crankcase cover and filling the clutch with swarf.

Ominously this isn't the first time. I had a similar occurrence with a 175 GT years back. It suddenly started cutting out and backfiring. Looking down at an unsteady 10mph I was horrified to see what appeared to be a large metallic slug eccentrically boring it's way through the dynamo cover on the crankcase.
A hasty pull in revealed that the bolt holding the auto advance and the armature had worked loose and spun it's way through the points inspection cover, neatly obliterating some of the cast script which now read: MOTO MOR I. This, I believe , is Italian for dead motorcycle.

Oh, and yesterday the centre stand broke , one leg cracked just below the horseshoe..the unlucky one at the neck of the centre stand.
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